Design and Development of Constant Stress Composite Cantilever Beam

Authors: Vinod B. Suryawanshi, Ajit D. Kelkar

Abstract:

Composite materials, due to their unique properties such as high strength to weight ratio, corrosion resistance, and impact resistance have huge potential as structural materials in automotive, construction and transportation applications. However, these properties often come at higher cost owing to complex design methods, difficult manufacturing processes and raw material cost. Traditionally, tapered laminated composite structures are manufactured using autoclave manufacturing process by ply drop off technique. Autoclave manufacturing though very powerful suffers from high capital investment and higher energy consumption. As per the current trends in composite manufacturing, Out of Autoclave (OoA) processes are looked as emerging technologies for manufacturing the structural composite components for aerospace and defense applications. However, there is a need for improvement among these processes to make them reliable and consistent. In this paper, feasibility of using out of autoclave process to manufacture the variable thickness cantilever beam is discussed. The minimum weight design for the composite beam is obtained using constant stress beam concept by tailoring the thickness of the beam. Ply drop off techniques was used to fabricate the variable thickness beam from glass/epoxy prepregs. Experiments were conducted to measure bending stresses along the span of the cantilever beam at different intervals by applying the concentrated load at the free end. Experimental results showed that the stresses in the bean at different intervals were constant. This proves the ability of OoA process to manufacture the constant stress beam. Finite element model for the constant stress beam was developed using commercial finite element simulation software. It was observed that the simulation results agreed very well with the experimental results and thus validated design and manufacturing approach used.

Keywords: Beams, Composites, Constant Stress, Structures.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1099044

References:

[1] A. Zucchelli, M.L.Focareteb, C. Gualandib and S. Ramakrishna, "Electrospun nanofibers for enhancing structural performance of composite materials." Polymers for Advanced Technologies, 22, (2011), pp. 339-349.
[2] A.D. Kelkar, R. Mohan, R. Bolick, S. Shendokar, "Effect of nanoparticles and nanofibers on Mode I fracture toughness of fiber glass reinforced polymeric matrix composites." Materials Science and Engineering: B,168, 2010, pp. 85-89.
[3] Linking Transformational Materials and Processing for an Energy Efficient and Low-Carbon Economy: Creating the Vision and Accelerating Realization, Innovation Impact Report, The Minerals, Metals and Materials Society (2011)
[4] S. Yadav, K. K. Pathak, and R. Shrivastava. "Shape Optimization of Cantilever Beams Using Neural Network." Applied Mathematical Sciences 4,2010, pp.1563-1572.
[5] Y. Hsu,S. D. Sheppard, and D. J. Wilde. "The curvature function method for two-dimensional shape optimization under stress constraints." Computers & structures 55, ,1995,pp.647-657
[6] J. Giordano,and Y. Burtschell, "Confrontation of Genetic Algorithm Optimization Process with a New Reference Case: Analytical Study with Experimental Validation of the Deflection of a Cantilever Beam." International Journal of Advanced Science and Technology,49,2012, pp.105-118.
[7] P.Reddy, K. Bhargavi,C.Nagaraju, Tailoring of composite cantilever beam for maximum stiffness and minimum weight , IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE), 9,2013,pp. 65-73.
[8] E. P.Popov,and T. A. Balan. Engineering mechanics of solids. Vol. 2. Englewood Cliffs, NJ, Prentice Hall, 1990.
[9] P.Dhurvey,and N. D. Mittal. "Review on Various Studies of Composite Laminates with Ply Drop-Off." Journal of Engineering & Applied Sciences 8,2013.
[10] A. S. T. M. "D3039/D3039M–00." Standard test method for tensile properties of polymer matrix composite materials,2000.B. Smith, “An approach to graphs of linear forms (Unpublished work style),” unpublished.
[11] D.K.Shinde, Effect of Electrospun Nanofibers on the Short Beam Strength of Laminated Fiberglass Composite, Ph.D dissertation, North Carolina A&T State University, 2014